BARK AS ROAD BUILDING MATERIAL IN SWEDEN /IN NORWEGIAN/

BARK FROM PINE AND FIR HAS BEEN TESTED IN SWEDEN FOR TEN YEARS AND HAS PROVED TO BE A GOOD ROAD BUILDING MATERIAL. THREE PROPERTIES THAT MAKE BARK EFFICIENT IN ROAD CONSTRUCTION ARE ITS FROST RESISTANCE, ITS BEARING CAPACITY, AND ITS LIGHT WEIGHT. BARK IS MOSTLY USED AS A FROST RETARDING MATERIAL IN ORDER TO PREVENT DAMAGES DUE TO FROST HEAVING. IN SOME CASES, BARK HAS BEEN THE LIGHT WEIGHT INGREDIENT IN THICK EMBANKMENTS ON SOFT GROUND. THE GRAVEL BASE ON THE BARK LAYERS, WHICH IS LAID DIRECTLY ON THE MOIST SUBGRADE, VARIES BETWEEN 30 AND 60 CM. ANY PRONOUNCED DAMAGES HAVE NOT DEVELOPED ON THESE ROADS. THE TRAFFIC, HOWEVER, HAS NOT BEEN HEAVY ON THE ROADS WITH THE MINIMUM THICKNESS OF THE BASE. MEASUREMENTS SHOW THAT ROAD SERVICEABILITY IS HIGH. THE BARK LAYER ALSO EFFECTIVELY REDUCES THE FROST HEAVING. RUTTING HAS NOT BEEN RECOGNIZED ON ROADS WITH BARK LAYERS, AND NO SETTLEMENTS. IN ORDER TO PREVENT LONGITUDINAL FROST CRACKS THE BARK IS LAID IN A WEDGE. BY MEASURING THE FROST PENETRATION AND AIR TEMPERATURE, THE RELATION BETWEEN FREEZING INDEX AND FROST DEPTH IN A BARK LAYER IS DETERMINED AND CAN BE PLOTTED. FROM METEOROLOGICAL DATA THE DISTRIBUTION OF WINTERS WITH VARYING FREEZING INDEX CAN BE CALCULATED. IF THE FREEZING INDEX FOR THE SITE IN QUESTION IS KNOWN, THE THICKNESS OF THE BARK LAYER, WHICH JUST STOPS THE FROST PENETRATING INTO THE SUBGRADE, CAN BE FOUND FROM THE KNOWN RELATION BETWEEN FREEZING INDEX AND FROST DEPTH.

  • Supplemental Notes:
    • No 5, pp 5-13, 11 FIG, 1 TAB, 6 REF
  • Corporate Authors:

    Royal Norwegian Council Sci & Ind Res

    ,    
  • Authors:
    • Gandahl, R
  • Publication Date: 1971-12

Subject/Index Terms

Filing Info

  • Accession Number: 00238040
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Apr 2 1972 12:00AM